The potency of standard 'on as such' or 'as is basis' must be considered in case if standard is not dried before use.
General Formula for Assay Calculation of As Is Basis or As Such Basis
Formula for Assay Calculation of As Is Basis or As Such Basis from Dried Basis
Formula Assay Calculation of As Is Basis or As Such Basis from Anhydrous Basis
Formula Assay Calculation of As Is Basis or As Such Basis from Solvent Free Basis
The assay content limit in almost all pharmaceutical monograms is defined on anhydrous basis. The assay test of a substance intended for medicinal application is carried out in standard analytical procedures without being rendered to anhydrous condition. Assay on an as-is basis refers to the assay test outcome. Since water is not regarded as an impurity in substances intended for medicinal use, the results of the water content test are included in the assay results in their current state. Using an industry-accepted method for assay on anhydrous basis, the water is mathematically accounted for in assay on as-is basis. The commonly used formula is written as (assay on as-is basis x 100)/(100 - % water), and the result is known as anhydrous assay.